Fluid pressure mechanism



y 1945. w. A. EATON FLUID PRESSURE MECHANISM 3 Sheets-Sheet 1 Filed Dec. 16, 1942 Wilfred 141 :0102. 71 H 0MQ L a mm 8 t mm 8 m NN\ mm E U WW 0% I m kw Q QN N 0G Q ,1 .1 9* \N a v ,rl aw mm mm, wn m mm 0% m QM 9v on 11 umw WW 9 f l 4 II a e m u Q U Q Q Q \Q Q m W 0% ON mm on aw W. A. EATON FLUID PRESSURE MECHANISM May 22, 1945.

Filed Dec. 16, 1942 3 Sheets-Sheet 2 ila-fil/ H Qvwe/wfo c. p'lfred Eafion.

llqia i H y 1945. w. A. EATON 2,376,588

FLUID PRESSURE MECHANISM Filed Dec. 16, 1942 5 Sheets-Sheet 3 Q N R Q v Q \9 R i: Q 8 a g 9: r 3n n R I m k W a a giwucwfo o Wp'lfredA.EaiOn,

Patented May 22, 1945 UNITED STATES PATENT OFFICE FLUID PRESSURE MECHANISM Wilfred A. Eaton, Elyria, Ohio, assignor to Bendlx-Westinghouse Automotive Air Brake Company, Elyria, Ohio, a corporation of Delaware Application December 16, 1942, Serial No. 469,259

20 Claims.

This invention relates to fluid compressing systems and more particularly to mechanism for producing fluid pressure under substantially high ressures.

It is well known by those skilled in the art that energy, in the form of heat, is generated when a fluid is compressed, with the temperatures produced corresponding to the increased pressure of the fluid. Since machines, such as fluid compressors, must be maintained below certain temperatures during operation thereof, the compression ratio of fluid compressors is limited. In view of the foregoing, it has become conventional practice to utilize multi-stage compressors for producing fluids under substantially high pressures. Conventional high pressure fluid compressors are therefore large bulky structures, of great mass, and of intricate design requiring extensive costs for the manufacture thereof. Compressors having the foregoing characteristics not only consume great energy during a short period of operation thereof but are also inadequate when employed in instances wherein weight of the equipment is of primary consideration, for example, in connection with systems for providing the energy medium to operate the controls of an aircraft.

It is, therefore, an object of the present invention to provide a novel fluid compressing system that overcomes the disadvantages enumerated heretofore.

Another object is to provide a novel fluid compressing system, employing a single stage compressor, for producing fluid under substantially higher pressures than the pressure of the fluid obtained upon operation of the single stage compressor alone.

Another object is to provide a fluid compressing system including a single stage fluid compressor and a novel arrangement for automatically intermittently supplying previously compressed fluid to the compressor for further increasing the pressure of such fluid.

Still another object of the present invention is to provide a fluid compressing system of the foregoing character including manually operable means for preventing further recompression of fluid pressure and with the system further characterized that the compressor automatically continually recirculates fluid pressure in a portion of the system to effectively unload the compressor.

Still another object is to provide in a fluid compressing system having a single stage fluid compressor and a novel arrangement for automatically intermittently recompressing the fluid pressure, a novel construction for automatically terminating recompression of fluid pressure and for maintaining recirculation of fluid pressure throughout a portion of the system when fluid under a predetermined substantially high pressure is obtained.

A still further object of the invention is to provide a fluid compressing system which continually provides a source of fluid under a substantially high constant pressure and a source of fluid under a substantially lower constant pressure.

Other objects and novel features of the present invention will appear more fully hereinafter from the following detailed description when considered in connection with the accompanying drawings which illustrate several embodiments of the invention. It is to be expressly understood, however, that the drawings are employed for purposes of illustration only and are not designed as a definition of the limits of the invention, reference for the latter being had to the appended claims.

In the drawings, wherein similar reference characters denote corresponding elements throughout the several views:

Fig. 1 is a diagrammatic showing, partly in section, of a fluid compressing system embodyin the principles of the present invention;

Fig. 2 is a diagrammatic illustration of a further embodiment of the invention, and

Fig. 3 is a diagrammatic showing of a still further embodiment of the invention.

With reference more particularly to Fig. l of the drawings, a fluid compressing system constructed in accordance with the principles of the present invention is disclosed therein including a single stage fluid compressor l0 driven by any suitable prime mover, not shown, and reservoirs Ii and 2 for receiving fluid pressure. The input valves of the compressor II] are connected to atmosphere, or to any suitable source of fluid, through conduit I3 and one-Way check valve M. The discharge from the compressor i0 is fed to the reservoir ll through conduit l5, a pressure responsive valvular device Hi, the purpose of which will appear more fully hereinafter, and conduit ll. Upon operation of the compressor Hi the source of fluid applied thereto through the conduit i3 is compressed a number of times determined by the compression ratio of the compressor i0, while the fluid pressure discharged from the compressor is stored in the reservoir Ii.

As mentioned heretofore, one of the objects of the present invention is to provide a fluid com pressing system, incorporating a single stage fluid compressor, of such construction that a source of fluid under a substantially high pressure, greater than the pressure of the fluid ordinarily produced upon operation of a single stage compressor, is obtained therefrom. In order to accomplish the foregoing, means are provided for periodically transferring the fluid pressure stored in the reservoir II to the input of the compressor l and for simultaneously periodically applying the fluid pressure discharged from the compressor to the reservoir l2 in accordance with the pressure of the fluid storedin the reservoir As shown, the foregoing means comprises the pressure responsive valvular device l5 which functions to close the fluid connection between the conduits l5 and I1 and to form fluid communication between the conduit l5 and the reservoir l2, by way of conduit l8 and one-way check valve l3, whenever a source of fluid pressure is applied thereto through conduit 20. The foregoing means also includes a connection between the reservoir I l and the input of the compressor I 0. The latter connection comprises the conduit I3, a conduit 2| connected to the conduit I3 between the compresser l0 and the check valve l4, and a pressure responsive valvular device 22 having connections with the reservoir II and the conduit 2 l. The valvular device 22 normally functions to prevent the flow of fluid pressure from the reservoir II to the conduit 2|, however, upon application of fluid pressure thereto by way of conduit 23, the valvular device 22 is operated to form a connection between the reservoir II and the input of the compressor I0.

In order to control operation of the pressure responsive valvular devices l3 and 22 in accordance with the pressure of the fluid in the reservoir II, a pressure responsive governor 24 is provided. The input of the governor 24 is connected to the reservoir through conduit 25 while the output thereof is connected through conduit 25, manually operable valvular device 21 and conduit 23, to the conduit 20 and to conduit 23, the latter conduit being connected to the conduit 23 by way of a double check valve 30. The governor 24 includes means responsive to application of a predetermined pressure thereto, through the conduit 25, for forming a fluid connection between the conduits 25 and 25, and is constructed in such a manner as to maintain communication between the conduits 25 and 25 until the pressure of the fluid applied thereto drops to a second predetermined value, substantially less than the predetermined value previously mentioned. Therefore the pressure responsive governor 24 operates to form a fluid connection between the reservoir II and the conduits 20 and 23 whenever the pressure of the fluid in the reservoir builds up to a predetermined value and to maintain such connection until the pressure of the fluid in the reservoir drops to a substantially lower value. A device constructed in accordance with the principles disclosed in the U. S. patent to B. S. Aikman No. 1,754,218, dated April 15, 1930, adequately serves the purpose of the pressure responsive governor 24.

As previously mentioned, the pressure responcylindrical body portion 32 having an output chamber 33 formed therein which is in continuous communication with the conduit IR. A body portion 34 is secured to the lower end of the body portion 32 in such a manner to form an input chamber 35 into which the fluid pressure from the compressor l0 continuously discharges. The body portion 35 includes an output chamber 35 connected to the conduit H, A circular opening 31 is provided in the body portion 34, between the chambers 35 and 36, for normally allowing fluid communication between the latter chambers. The valvular device l5 also includes a body portion 33 secured to the upper side thereof. A pressure responsive diaphragm 39 is clamped between the body portions 32 and 38 thus defining chambers 40 and 4|. A spring 42 is included within the chamber 40 between the diaphragm 39 and the body portion 32 to urge the diaphragm 39 upwardly, as viewed in the drawings, while the chamber 4| is in communication with conduit 20. A valve stem 43 is mounted for movement within the body portion 32, having one end thereof rigidly secured to the diaphragm 33 while the other end extends through an opening 44, in the casing 32, and terminates within the chamber 35 in a ball valve 45. When the pressure responsive valvular device I5 is in the normal condition thereof as shown, that is, when fluid pressure is not applied thereto through the conduit 20, the diaphragm 39 and the valve stem 43 are urged upwardly as viewed in the drawings, by the tension of the spring 42, to maintain the ball valve 45 in contact with the periphery of the opening 44. With the foregoing conditions, fluid communication is maintained between the conduits l5 and I! by Way of chambers 35 and 36 while the flow of fluid pressure to the chamber 33 is blocked by the ball valve 45. Whenever fluid pressure is applied to the chamber 4| by way of the conduit 25, the diaphragm 39 is moved downwardly against the tension of the spring 42 to thus move the ball valve 45 away from the opening 44 and into engagement with the upper periphery of the opening 31, With the latter conditions, fluid communication is maintained between the conduits i5 and I3 while the connection between the conduits l5 and I1 is terminated The pressure responsive valvular device 22, as previously mentioned, is constructed in such a manner as to normally prevent the flow of fluid pressure from the reservoir II to the conduit 2| and is responsive to application of fluid pressure thereto, through the conduit 23, to allow fluid communication between the reservoir II and the conduit 2|. As shown, the valvular device 22 comprises a cylindrical body portion 43 having a chamber 41 formed therein to which the conduit 2| is connected. The upper end of the bbdy portion 45 is closed by a body portion 43 to thus form a chamber 49 that is in continuous communication with the reservoir The valvular device 22 further includes a body portion 50 secured to the lower end of the body portion 45, with a pressure responsive diaphragm 5| clamped between the body portions 45 and 50, thus defining chambers 52 and 53. A spring 54 is included within the chamber 52, between the diaphragm 5| and the body portion 46, to continually urge the diaphragm downwardly as viewed in the drawings/while fluid pressure is supplied to the chamber 53 through the conduit 23 to move the diaphragm 5| upwardly against the tension of the spring 54. One end of a valve stem 55 is rigidly secured to the diaphragm 5| at the center thereof while the other end of the valve stem extends through an opening II in the .body portion II and terminates within the chamber II. A ball valve 51 is secured to the terminating end of the valve stem II, and is normally urged into contact with the periphery of the opening II, due to the downward force applied to the diaphragm II and the valve stem 55 by the tension of the spring ll, to thus normall prevent the flow of fluid pressure between chambers 41 and It, However, whenever fluid pressure is supplied to the chamber 22, the diaphragm II is moved upwardly against the tension of the spring I to thus move the ball valve 51 away from the opening I! and to allow the flow of fluid pressure from the reservoir ii to the conduit 2i.

It is to be expressly understood. therefore, that the pressure responsive valvular devices II and 22 normally occupy the positions thereof shown in the drawings, in which case the input fluid to the compressor III is supplied by way or the check valve it while the fluid pressure discharged from the compressor is fed to the reservoir ii. When the pressure of the fluid stored in the reservoir Ii builds up to a predetermined value the pressure responsive governor 24 operates to form a fluid connection between the conduits 25 and 26. Whenever the manually operable valvular device 21 is in the position shown in the drawings, the fluid pressure from the conduit 26 may be supplied to the conduits 20 and 28 by way of the conduit 28. Fluid pressure is, therefore, simultaneously supplied to the chambers 4i and I53 of the valvular devices It and 22 respectively. The application of fluid pressure to the chambers 4i and 53 simultaneously operates the valvular devices l6 and 22 in a manner described heretofore, The valvular device 22 functions to open a fluid pressure communication between the reservoir Ii and the input valves of the compressor in while the valve device It operates to close the connection between the discharge of the compressor and the reservoir ii and to form a connection between the conduit i and the reservoir i2. After the valvular devices i8 and 22 operate to form the foregoing connections the compressor iii functions to recompress the fluid pressure stored in the reservoir ii. The fluid discharged from the compressor in under these conditions is at a pressure a number of times greater than the pressure of the fluid previously stored in the reservoir II by a degree corresponding to the compression ratio of the compressor iii. The compressor Ill continues to recompress the fluid stored in the reservoir ii until the pressure of the fluid in the reservoir i i is reduced to such a value that the pressure responsive governor 24 operates to close the fluid connection between the conduits 25 and 26 and to exhaust the conduit 26 to atmosphere. When the conduit 26 is exhausted to atmosphere the pressure of the fluid in the chambers 4i and 53 is reduced and the valve devices it and 22 return to normal positions thereof wherein the connection between the reservoir ii and the conduit 2i is closed and wherein the fluid pressure discharged from the compressor I0 is fed to the'reservoir ii. The compressor i0 thereafter functions to compress fluid received through the check valve ll while the fluid pressure discharged therefrom is stored in the reservoir I I, until the pressure of the fluid in the latter reservoir attains a sumcient value to operate the pressure responsive governor 24 in a manner previously described. With the foregoing arrangement, fluid under extremely high pressures .H by a degree substantially equal to the compression ratio of the compressor II.

In order to maintain the pressure of the fluid in the reservoir i2 at a predetermined, substantially constant value, the reservoirs i2 and ii are interconnected through a suitable pressure regulating valve ll by means of conduits so and N. The pressure regulating valve is is of conventional construction and functions to prevent communication between the conduits is and until the pressure or the fluid in the reservoir l2 builds up to a predetermined value, at which instant the valve 50 operates to form a connection between the conduits i9 and 80. With this arrangement, the fluid pressure stored in the reservoir i2 is maintained at a substantially constant, predetermined value determined by the adjustment of the pressure regulatorvalve 58. The fluid pressure in the reservoir i2 is fed, through conduit 6 i, to devices, not shown, for controlling the operation thereof.

Means are also provided in connection with the novel fluid compressing system previously described for preventing further energization of the reservoir l2 with fluid pressure after the pressure of the fluid in the reservoir I2 builds up to a desired value. When the above means is operated, the pressure of the fluid stored in the reservoir ill builds up to a substantially constant value determined by the compression ratio of the fluid compressor iii. Such substantially constant fluid pressure may be employed for energizing the fluid pressure devices that operate upon application of fluid under substantially low pressures, A fluid compressing system incorporating the foregoing means is so characterized that the fluid pressure stored in the reservoir ii is continually recirculated through the compressor ill, whenever the pressure of the fluid in the reservoir ii builds up to a predetermined value, to thus effectively unload the compressor ill.

The foregoing means comprises the manually operable valvular device 21, the double check valve in and a conduit 62 forming a fluid connection between the valvular device 21 and the double check valve 30. More particularly, the valvular device 21 includes a cylindrical casing 63 having a valve member 62 mounted for rotation therein upon operation of a suitable manual control, not shown. The conduits 2B and 28 are connected, at substantially right angles with respect to each other, to the interior of the casing 63 while the conduit 62 and an exhaust conduit 65 are connected to the interior of the casing 63 at points substantially opposite the connected ends of the conduits 2B and 28, respectively. When the valve member 64 is in the position shown, fluid communication is maintained between the conduits 28 and 28 while the conduit 62 is ex hausted to atmosphere through the conduit 55. However, when the valve member 64 is rotated to a position at right angles to the position shown, the conduit 28 is exhausted through the conduit 65 while a fluid connection is formed between the conduits 2B and 62. With the valve member, 6| in the latter position, and whenever the pressure of the fluid in the reservoir I l is of a sufllcient value to operate the pressure responsive governor 2|, a connection is maintained between the conduits 25, and 28, and the conduit 32 is therefore energized with fluid pressure. Energization of the conduit 62 with fluid pressure therefore moves the valve member 88 of the double check valve 30, to-the right as viewed in the drawings, and the fluid pressure from the conduit 82 is applied to the chamber 53 of the pressure responsive valve device 22, by way of the conduit 23, thus Operating the valvular device 22 in a manner described heretofore.

With the foregoing arrangement therefore, whenever the valve member 64 is moved to a position at right angles to the position shown, the conduits 20 and 29 are exhausted to atmosphere through the conduit 85 and the pressure responsive valvular device I6 is maintained in the normal position thereof as shown, thus preventing the flow of fluid pressure to the reservoir I2. The fluid pressure discharged from the compressor I is therefore continually passed to the reservoir II at all times when the manually operable valvular device 21 is in the position referred to above. When the pressure of the fluid in the reservoir II is of a value insufficient to operate the pressure responsive governor 24 the compressor I0 receives fluid through the check valve I4. However, when the pressure of the fluid stored in the reservoir II builds up to a value so that the pressure responsive governor 24 operates to form a fluid connection between the conduits 25 and 26, fluid pressure is supplied to the chamber 53 by way of the conduit 62 thus operating the pressure responsive valvular device 22 to form a fluid connection between the reservoir II and the input of the compressor III. Under these conditions, the compressor I0 merely functions to recirculate the fluid pressure stored in the reservoir II. Since additional fluid is not supplied to the system, and furthermore, since no substantial changes in pressure occur throughout the system, substantially no load is applied to the compressor I0. Moreover, since the pressure responsive governor 24 functions when predetermined pressures are applied thereto, the pressure of the fluid in the reservoir II is maintained substantially constant. The fluid pressure in the reservoir Il may therefore be fed through output conduit 61 to any pressure responsive devices requiring application of low pressures for the operation thereof.

Another embodiment of the invention is shown in Fig. 2 of the drawings. The fluid compressing system shown in this embodiment is somewhat similar to the system previously described and disclosed in Fig. 1 of the drawings, and includes novel means for automatically preventing further energization of the reservoir I2 whenever the pressure of the fluid stored in the latter reservoir builds up to a predetermined value, as well as means for automatically rendering the system in a condition wherein fluid pressure is only supplied to the reservoir II, after the pressure of the fluid in the reservoir I2 builds up to such predetermined value, and for automatically recirculating the fluid stored in the reservoir I I after the pressure of the fluid stored in the latter reservoir builds up to a predetermined value.

As shown, the fluid compressing system disclosed includes the fluid compressor I0 having discharge ports thereof connected through the conduit I5 to the pressure responsive valvular device I6. The pressure responsive device It tween the conduit I5 and the reservoir II.

duit I1 and is responsive to application of fluid pressure thereto by way of the conduit 20 to interrupt the fluid connection between the' conduits I5 and I1 and to form a connection between the conduits I5 and I1 and to form a connection be- The pressure responsive valvular device 22 is also included for forming a connection between the reservoir II and the input of the compressor III whenever fluid pressure is supplied thereto through the conduit 23. In order to control operation of the pressure responsive valvular devices IG and 22 the pressure responsive governor 24 is provided. The governor 24 is responsive to the pressure of the fluid in the reservoir II for supplying fluid pressure to the conduit 26 whenever the pressure of the fluid stored in the reservoir II builds up to a predetermined value and for continually supplying fluid pressure to the conduit 23 until the pressure of the fluid in the reservoir II drops to a substantially lower value. In this embodiment, the conduit 26 is directly connected to the conduits 20 and 29 so that the pressure responsive devices I6 and 22 are operated whenever the pressure responsive governor 24 functions to form a fluid connection between the conduits 25 and 26. The portion of the fluid compressing system disclosed in Fig. 2 that has been described above operates in a manner similar to the arrangement disclosed in Fig. l.

The aforementioned means for preventing further energization of the reservoir l2 after the pressure of the fluid in the latter reservoir builds up to a predetermined value includes a pressure responsive governor l0 constructed in a manner similar to the pressure responsive overnor 24. The governor I0 is connected to the reservoir I2 through conduit II and therefore operates to from a fluid connection between the conduit II and an output conduit I2 whenever the pressure of the fluid in the reservoir I2 builds up to a predetermined value. It is to be expressly understood that the governor 10 is adjusted to respond to application of a predetermined pressure that is a number of times greater than the pressure required for operation of the governor 24. The conduit I2 is connected to the conduit 23 through the double check valve 30.

Whenever the pressure of the fluid in the reservoir I2 builds up to a sufncient value to operate the governor Hi fluid pressure is applied to the check valve 30 by way of the conduit ll. Since the pressure of the fluid applied to the check valve 30 through the conduit 12 is a number of times greater than the pressure of the fluid applied to the check valve 30 by way of the conduit 29, the fluid pressure from the conduit 12 is applied to the valvular mechanism 22 through the conduit 23 notwithstanding the presence of fluid pressure in the conduit 29. The valvular device 22 is therefore operated to form a connection between the reservoir I I and the input of the compressor I 0 whenever pressure in the reservoir I2 builds up to a sufficient value to operate the governor 10. At the instant the connection is formed between the reservoir I I and the compressor I0 a substantial drop in pressure of the fluid stored in the latter reservoir occurs and the governor 24 functions to exhaust the conduit 20 to atmosphere to thereby operate the valvular device It and to terminate the fluid connection between the conduit I5 and the reservoir I2. The compressor III thereafter functions to recirculate the fluid pressure stored in the reservoir II in a manner heretofore described relative to the system disclosed in Fla. 1, until such time as the pressure of the fluid in the reservoir l2 isreduced a suflicient degree, upon utilization of the fluid pressure stored therein through the conduit 6|, to allow the governor 10 to operate, thus terminating the connection between the conduits H and I2 and exhausting the latter conduit to atmosphere. The fluid compressing system then operates in a manner fully described heretofore .to again intermittently supply fluid pressure to the reservoir l2 until the pressure stored therein builds up to a sufllcient value to operate the governor 10. It is appreciated that the pressure of the fluid in the reservoir H may not immediately drop to a suflicient value to operate the governor 24, and consequently the valvular device It, at the instant a fluid connection is formed between the reservoir II and the input of the compressor l0, upon application of fluid pressure to the valvular device 22 through the conduit 12. In viewrof the foregoing, fluid pressure may be supplied to the reservoir I2 after the governor 10 has operated to energize the conduit 12 and thus build up the pressure of the fluid stored in the-reservoir 12 to some value higher than the predetermined value deterressure of the fluid in the reservoir l2 will be only slightly increased.

Still another embodiment of the invention is shown in Fig. 3 of the drawings. The fluid compressing system disclosed in this embodiment is also similar to the system shown in Fig. 1 of the drawings and includes other novel means for controlling the pressure of the fluid stored in the reservoir H after the fluid pressure in the reservoir I2-is built up to some desired value. As shown, the system disclosed in Fig. 3 includes the fluid compressor Hi, the reservoirs II and i2, and the pressure responsive valvular devices l6 and 22 interconnected in a manner similar to the arrangement shown in Fig. 1. Moreover, the reservoirs l2 and H are interconnected through the pressure regulator valve 58 by means of conduits 59 and in a manner similar to the connection between the reservoirs II and I2 of Fig. l.

The reservoir i I is connected, by way of conduit I5, the manually operable valvular mechanism 21 and the conduit 16 to the pressure responsive governor 24, whenever the valve member of the valvular device 21 is in the position shown. The governor 24 is also connected through the conduit 28 to the conduits 20 and 29 and is responsive to a predetermined pressure of the fluid in the reservoir to form a fluid connection be.- tween the latter reservoir and the pressure responsive valvular devices l6 and 22 in a manner similar to the arrangements previously described. The portion of the fluid compressing system shown in Fig. 3, that has been described above, therefore operates in such a manner to alternately feed the output of the compressor Iii to the reservoirs H and I2, thus storing fluid at substantially high pressure in the latter reservoir. When 'the pressure of the fluid in the reservoir l2 builds up to a value that corresponds to the adjustments of the pressure regulator valve 58, the pressure in excess of such value is fed to the reservoir H through the conduit 60.

A pressure regulator valve 'I'I, constructed in a manner similar to the pressure regulator valve 58, is connected to the valvular mechanism' 21, through the conduit 18, and to the conduit 2| by way of conduit 19. Whenever the valve member 84 is moved to a position at right angles to that shown inthe drawings, the conduit I0 is exhausted to atmosphere through the conduit 85 and a fluid connection is formed between. the conduits 15 and I8. When the valve member 64 is moved to the latter position the conduits 20 and 29 are exhausted to atmosphere; through the governor 24, and the valvular mechanisms [6 and 22 move to the normal positions thereof whereinthe output of the compressor III is fed to the reservoir II .and the connection between the latter reservoir and the input of the compressor I0 is closed. The pressure regulator valve 11 is responsive to a predetermined pressure of the fluid in the reservoir I l to form a connection between the latter reservoir and the conduit 2|. Whenever the pressure of the fluid in the reservoir H is below a suflicient value to operate the valve 11 the compressor l0 operates to compress fluid supplied through the check valve H which is discharged to the reservoir Ii. Whenever the pressure of the fluid in the reservoir Ii builds up to a value greater than the pressure required to operate the valve 11, the latter valve operates to form a connection between the reservoir H and the conduit 2|. The compressor l0 therefore merely functions to recirculate the fluid pres- .sure in excess of the predetermined value determined by the valve thus substantially reducing the load on the compressor. Since the valve I1 operates to close the connection between the reservoir H and the conduit 2! whenever the pressure of the'fluid in the latter reservoir drops to a predetermined value, fluid under substantially constant pressure is maintained in the reservoir ll.

Operation of the fluid compressing system disclosed in Fig. 1 of the drawings may be more readily understood by assuming that no fluid pressure is present within the system and that the compressor In is not operated. Under these conditions, the pressure responsive valvular devices IB and 22 are in the position shown in the drawings and the output of the compressor i0 is connected to the reservoir ll. Upon operation of the compressor Ill fluid is drawn through the check valve l4 and compressed a number of times equal to the compression ratio of the compressor III, while the fluid pressure discharged from the compressor I0 is fed through the conduits l5 and I! to the reservoir II. The foregoing operation continues until the pressure of the fluid stored in the reservoir-l l builds up to a suflicient value to operate the pressure responsive governor 24 at which instant the conduits 20 and 29 are energized with fluid pressure to simultaneously operate the pressure responsive valvular devices l6 and 22. When the valvular device I6 is energized with fluid pressure, a fluid communication between the conduits i5 and I8 is formed'and the fluid connection between the conduit l5 and the reservoir II is closed, while the pressure responsive valvular device 22 functions to form a fluid connection between the reservoir II 'and the input'of the compressor ill by way of the conduits l3 and 2|. After the valvular devices l8 and 22 operate in the foregoing manner the fluid amount substantially equal to the compression ratio of the compressor. The fluid under high pressure discharged in the compressor II is sup plied to the reservoir I2 through the conduits II and II. The compressor II continues to recompress the pressure stored in the reservoir II until the pressure of the fluid therein drops to a predetermined value at which instant the governor 24 operates to terminate the fluid connection between the conduits 2i and 26 thus exhausting the conduits 20 and 29 to atmosphere through the governor 24. The pressure responsive valvular devicese I6 and 22 then return to the normal positions shown, terminating the connections between the reservoir II and the input of the compressor III and between the discharge port of the compressor Ill and the reservoir I2 and to form a fluid connection between the discharge of the compressor I and the reservoir I I. The check valve is functions to prevent the fluid pressure stored in the reservoir I2 from flowing to the valvular device I 6 and hence to the reservoir II during the time the valvular device IB is operating.

The fluid compressing system continues to charge the reservoir II with fluid pressure and to automatically recompress the fluid stored in the latter reservoir and to store the recompressed fluid-in the reservoir I2 until the pressure of the fluid in the latter reservoir builds up to a predetermined value determined by the pressure regulator valve 58.

When the pressure of the fluid in the reservoir I2 builds up to a desired value, such as the predetermined pressure determined by the pressure regulator-valve 58, or when it is desired to maintain a source of fluid pressure of a substantially low value, the valve member 64 of the manually operable valvular device 21 is moved to a position at right angles to that shown in the drawings, thus exhausting the conduits and 29 to atmosphere, through the conduit 65, to form a fluid connection between the conduits 28 and 62. When the valvular device 21 is operated in the foregoing manner, the reservoir I2 is eliminated from the system and the fluid pressure discharged from the compressor I0 is continually supplied to the reservoir I I. In the event that the pressure of the fluid in the reservoir I I is of an insuiiicient value to operate the governor 24 fluid is supplied to the input of the compressor III by way of the check valve I4. However, when the pressure of the fluid in the reservoir .II builds up to a sufllcient value to operate the governor 24, a connection is formed between the reservoir II and the input of the compressor ID. The compressor thereafter merely functions to recirculate the fluid pressure stored in the reservoir II.

The fluid compressing system disclosed in Fig. 2 of the drawings operates in a manner similar to that disclosed in Fig. l to store fluid under high pressure in the reservoir I2. When the pressure of the fluid in the reservoir I2 builds up to a predetermined value the pressure responsive governor 10 operates to energize the conduit 12 with fluid pressure to thus operate the pressure responsive valvular device 22 independently of the fluid pressure supplied thereto through the conduit 29. The connection between the reservoir II and the input of the compressor III is maintained open whenever the pressure of the fluid in the reservoir I2 exceeds the predetermined value determined by the adjustment of the pressure responsive governor Ill. The compresamuse sor I ll therefore continually recompresses the fluid pressure stored in the reservoir II. A drop in pressure of the fluid in the reservoir I I immediately occurs and the governor 24 functions to functions to exhaust the conduit 12 to atmosphere and thus allowing the system to operate in a manner described heretofore to again charge I the reservoir I2 with fluid pressure.

Operation of the embodiment of the invention disclosed in Fig. 3 of the drawings is similar to the operation of the system disclosed in Fig. 1, whenever the valve member 84 of the manually operable valvular device 21 is in a position as shown in the drawings. However. when the pressure of the fluid in the reservoir I2 builds up to a desired value or whenever a source of fluid of substantially constant pressure is desired, the valve member 64 is moved to a position at substantially right angles to the position shown. When the valve member 64 is moved in the foregoing manner the conduits 20 and 29 are exhausted to atmosphere and the pressure responsive valvular devices I6 and 22 return to the normal positions thereof wherein the conduit I5 is connected to the reservoir II. The compressor l0 then compresses fluid derived by way of check valve I4 until the pressure of the fluid stored in the reservoir II builds up to a sufficient value to operate the pressure regulator valve 11. When the pressure regulator valve 11 operates, a con nectionis formed between the reservoir I I and the input of the compressor III so that the compressor functions to recirculate the fluid pressure in the system and no additional fluid is supplied thereto by way of the check valve I4.

There is thus provided by the present invention a novel fluid compressing system, employing a single stage, light-weight, fluid compressor, that is capable of producing fluid under substantially high pressures, substantially equal to the pressure of fluid obtained from conventional multistage fluid compressors. Furthermore, the

fluid compressing systems disclosed in the several embodiments of the present invention are not only capable of producing a source of fluid under substantially high pressures but also are so characterized to continually maintain a source of fluid under a substantially lower pressure. Moreover, automatic as well as manually operable arrangements have been disclosed herein for controlling operation of fluid compressing systems of the above character in such a manner that the fluid compressor functions to recirculate fluid pressure throughout a portion of the system. thus efl'ectively unloading the compressor, when a source of fluid under a predetermined pressure is built up in the system or when fluid under a desired pressure is obtained.

Although several embodiments of the present invention have been illustrated and described in detail herein it is to be expressly understood that various changes and substitutions may be made therein without departing from the spirit of the invention as well understood by those skilled in the art. Reference, therefore, will be had to the appended claims for a definition oi! the limits of the invention.

fluid to said compressor, a first reservoir, means normally charging said first reservoir with fluid pressure from said compressor, a second resere voir, and means responsive to a predetermined value of the pressure of the fluid in said first reservoir iorautomatically supplying the fluid pressure in said first reservoir to said compressor and for charging said second reservoir with fluid pressure from said compressor.

2. A system for compressing fluid comprising a fluid compressor having input and output conduits, means connecting a source of fluid to said input conduit, a plurality of reservoirs, a-normally open connection between said output conduit and one of said reservoirs, a normally closed connection between said output conduit and another oi said reservoirs, a normally closed connection between said one reservoir and said input conduit, and means responsive to a predetermined pressure of the fluid in said one reservoir for simultaneously closing said normally open conneciion and opening said normally closed connections.

3. A system for compressing fluid comprising a fluid compressor. means connecting a source of fluid to said compressor, a first reservoir, means normally charging said first reservoir with fluid pressure from said compressor, a second reservoir, and automatic means for periodically supplying the fluid pressure in said first reservoir to said compressor and for charging said second reservoir with fluid pressure from said compressor, whereby charging of the first reservoir is prevented and the second reservoir-is charged to a pressure greater than that in the first reservoir.

4. A system for compressing fluid comprising a. fluid compressor, means connecting a source of fluid to said compressor, a first reservoir, means normally charging said first reservoir with fluid pressure from said compressor, a second reservoir, means responsive to a predetermined pressure or the fluid in said first reservoir for supplying the fluid pressure in said first reservoir to said compressor, and other means responsive to said predetermined pressure of the fluid in said first reservoir for charging said second reservoir with fluid pressure from said compressor.

5. A system for compressing fluid comprising a fluid compressor, means connecting a source of fluid to said compressor, a first reservoir, means normally charging said first reservoir with fluid pressure from said compressor, a second reservoir, and means responsive to a predetermined pressure oi the fluid in said first reservoir for automatically simultaneously supplying the fluid pres sure in said first reservoir to said compressor and for charging said second reservoir with fluid pressure from said compressor. I

6. A system for compressing fluid comprising a .source of fluid, a fluid compressor, a, plurality of reservoirs, means normally operative for supplying fluid pressure from said source to-the input of said compressor and for transferring the fluid pressure discharged from said compressor to one of said reservoirs and means responsive to the pressure of the fluid in said one reservoir for suppressure discharged from said compressor to one of said reservoirs, normally inoperative means or reservoirs, means normally operative for supplying fluid pressure from said source to the input of said compressor and for transferring the fluid for supplying fluid pressure in said one reservoir to said compressor and for transferring the fluid pressure discharged from said, compressor to another of said reservoirs, and means responsive to the pressure of the fluid in said one reservoir for simultaneously rendering said normally operative means inoperative and said normally inoperative means operative.

8. *A system for compressing fluid comprising a source of fluid, a fluid compressor, a plurality of reservoirs, means normally operative for supplying fluid pressure from said source to the input-of said compressor and for transferring the fluid pressure discharged from said compressor to one of said reservoirs, normally inoperative means for supplying fluid pressure in said one reservoir to said compressor and for transferring the fluid pressure discharged from said compressor to another of said reservoirs, and means responsive to the pressure oi. the fluid in said one reservoir for intermittently synchronously rendering said normally operative means inoperative and said normally inoperative means operative.

9. A system for compressing fluid comprising a fluid compressor, means supplying a source of fluid to said compressor, a first reservoir, means normally charging said first reservoir with fluid pressure from said compressor, a second reservoir,

and means responsive to a predetermined value of the pressure of the fluid in said first reservoir for automatically supplying the fluid pressure in said first reservoir to said compressor and for charging said second reservoir with fluid pressure from said compressor until the pressure of the fluid in said first reservoir drops to a second predetermined value substantially less than said predetermined value. p

10. A system for compressing fluid comprising a fluid compressor having input and output conduits, means connecting a source of fluid to said input conduit, a plurality of reservoirs, a normally open connection between said output conduit and one of said reservoirs, a normally closed connection between said output conduit and another of said reservoirs, a normally closed connection between said one reservoir and said input conduit, and means'responsive to a predetermined value of the pressure of the fluid in said one reservoir for simultaneously closing said normally open connection and opening said normally closed connections until the pressure of the fluid in said first reservoir drops to a second predetermined value substantially less than said predetermined value.

II. A system for compressing fluid comprising a source of fluid, a fluid compressor, a plurality of reservoirs, normally operative means for supplying fluid pressure from said source to the input of said compressor and for transferring the fluid pressure discharged from said compressor to one of said reservoirs, normally inoperative means for supplying fluid pressure in said one reservoir to said compressor and for transferring the fluid pressure discharged from said compressor to another of said reservoirs, and means operative when the pressure of the fluid in said one reservoir is between predetermined limits for maintaining said normally operative means in an inoperative state and said normally inoperative means in an operative state.

12. In a system ior compressing fluid. a fluidcompressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor. a normally open connection between the output of said compressor and one of said reservoirs, a normally closed connection between the output of said compressor and another of said reservoirs, first valvular means operable upon application of fluid pressure thereto for simultaneously closing said normally open connection and for opening said normally closed connection, a normally closed connection between said one reservoir and the. input of said compressor, second valvular means operable upon application 01' fluid pressure thereto for opening the last-named normally closed connection, and means responsive to the pressure of the fluid in said one reservoir for simultaneously applying fluid pressure to said first and said second valvular means.

13. In a system for compressing fluid, a fluid compressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor, a normally open connection between the output of said compressor and one of said reservoirs, a

thereto for opening thelast-named normally closed connection, and means responsive to a predetermined pressure of the fluid in said one reservoir for simultaneously supplying fluid pressure to said flrst and said second valvular means, the last-named means operable upon apredetermined drop in pressure of the fluid in said one reservoir for simultaneously exhausting said first and said second valvular means to atmosphere.

14. In a system for compressing fluid, a fluid compressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor, a normally open connection between the output of said compressor and one of said reservoirs, a normally closed connection between the output of said compressor and another of said reservoirs, first valvular means operable upon application of fluid pressure thereto for simultaneously closing said normally open connection and for opening said normally closed connection, a normally closed connection between said one reservoir and the input of said compressor, second valvular means operable upon application of fluid pressure thereto for opening the last-named normally closed connection, and means responsive to the pressure of the fluid in said one reservoir for periodcally simultaneously supplying fluid pressure to said first and said second valvular means and for simultaneously periodically exhausting said flrst and said second valvular means to atmosphere.

15. In a system for compressing fluid, a fluid compressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor, a normally open connection between the output of said compressor and one of said reservoirs, a normally closed connection between the output of said compressor and another of said reservoirs, first valvular means operable upon application of fluid pressure thereto for simultaneously closing said normally open connection and for opening said normally closed connection, a norcompressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor, a normally open connection between the output of said compressor and one of said reservoirs, a normally closed connection between the output of said compressor and another of said reservoirs, flrst valvular means operable upon application of fluid pressure thereto for simultaneously closing said normally open connection and for opening said normally closed connection, a normally.

closed connection between said one reservoir and the input 01' said compressor, second valvular means operable upon application of fluid pressure thereto for opening the last-named normally closed connection, means responsive to the pressure of the fluid in said one reservoir for simultaneously supplying fluid pressure to said first and said second valvular means, and means responsive to the pressure of the fluid in said another reservoir for supplying fluid pressure to said second valvular means independently of the lastnamed means.

17. In a system for compressing fluid, a fluid compressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor, a normally open connection between the output of said compressor and one of said reservoirs, a normally'closed connection between the output of said compressor and another of. said reservoirs, first valvular means operable upon application of fluid pressure thereto for simultaneously closing said normally open connection and for opening said normally closed connection, a normally closed connection between said one reservoir and the input of said compressor, second valvular means operable upon application of fluid pressure thereto for opening the last-named normally closed connection, means responsive to a predetermined pressure of the fluid in said one reservoir for simultaneously supplying fluid pressure to said flrst and said second valvular means and for exhausting said first and said second valvular means to atmosphere after the pressure of the fluid in said one reservoir drops a predetermined degree, and means responsive to the pressure of the fluid in said another reservoir for supplying fluid pressure to said second valvular means independently of the last-named means.

18. In a system for compressing fluid, a fluid compressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor, a normallyopen connection between the output of said compressor and one of said reservoirs, a normally closed connection between the output of said compressor and another of said reservoirs, first valvular means operable upon application of fluid pressure thereto for simultaneously closing said normally open connection and for opening said normally closed connection, a normally closed connection between said one reservoir and the input of said compressor, second valvular means operable upon application of fluid presasvasse for supplying fluid pressure to said second valvuiar means independently of the last-named means and for allowing the last-named means to supply fluid pressure to said second valvular means when the pressure of the fluid in said another reservoir drops a predetermined degree.

19. In a system for compressing fluid, a fluid compressor, a plurality of reservoirs, a source of fluid connected to the input of said compressor, a normally open connection between the output of said compressor and one of said reservoirs, a normally closed connection between the output of said compressor and another of said reservoirs, flrst valvular means operable upon application of fluid pressure thereto for simultaneously closing said normally open connection and for opening said normally closed connection, a normally closed connection between said one reservoir and the input of said compressor, second valvular means operable upon application of fluid pressure thereto for opening the last-named normally closed connection, means responsive to a predetermined pressure oi the fluid in said one reservoir for simultaneously supplying fluid pressure to said flrst and said second valvular means and for exhausting said flrst and said second valvular means to atmosphere alter the pressure of the fluid in said one reservoir drops a predetermined degree, means responsive to the pressure of the fluid in said one reservoir for simultaneously supplying fluid pressure to said first and said second valvular means, a second normally closed connection between said one reservoir and the input of said compressor, a valve device responsive to a predetermined pressure of the fluid in said one reservoir for opening the last-named connection and manually operable valve means for disconnecting the last-named means from said one reservoir and for forming a connection between said one reservoir and said valve device.

20. A system for compressing fluid comprising a source of fluid, a fluid compressor, a plurality of reservoirs, means normally operative for supplying fluid pressure from said source ,to the input of said compressor and for transferring the fluid pressure discharged from said compressor to one of said reservoirs, normally inoperative means for supplying fluid pressure in said one reservoir to said compressor and for transferring the fluid pressure discharged from said compressor to another or said reservoirs, means responsive to the pressure of the fluid in said one reservoir for simultaneously rendering said normally operative means inoperative and said normally inoperative means operative, and means including a valve for transferring fluid from said another reservoir to said one reservoir when the pressure of the fluid in said another reservoir exceeds a predetermined value.

- WILFRED A. EATON. 

